Greg
The Toja Grid brackets are fairly sturdy. They look good as well.
They did say that only certain wood will fit in the brackets. I used pressure treated lumber. I used a planer and sander to ensure the ends fit. Finished cedar 4”x4” would have been easier, but harder to find above 10’ lengths. Everything was stained before assembly.
I think they recommend not going over 12’ lengths. I agree with that, the pergola would be less stable. My pergola is 11’x10’ and 8’ high with the angled supports and moves a little bit even with the bracing.
The only knock I have is some of the internal weld are sketchy, poor quality. The welds fell out. I rewelded them, but for the price point, I shouldn’t have to. All in all, I’d do it again. I have some more work to do, but the basic pergola is up.